As the storm intensifies avalanche danger will increase rapidly. Consider what terrain is above you; avalanches starting in the alpine may run well into the alder! Space out when crossing run outs and regroup in safe spots.
Weather Forecast
An intense storm is headed our way. The timing is uncertain but we expect flurries with ~ 7cm today. The storm will intensify this afternoon with winds increasing to strong and up to 10cm overnight. Saturday will follow a similar pattern, with ~5cm during the day followed by another 10cm overnight. Sunday will clear and temps will plummet.
Snowpack Summary
10-20cm of powder overlies settled snow & windslabs in the alpine. The Nov 13 crust is buried ~60 and 100cm deep. In most areas the crust seems to be bonding well but is of most concern on S'ly aspects. Tests on a SW aspect, 2075m indicated that the crust may be triggered by light loads and that it is capable of propagating into a large avalanche.
Avalanche Summary
Light winds and only small amounts of snow over the past few days has resulted in little natural avalanche activity. Natural avalanches up to size 2 have been observed from steep, unskiable terrain. There have also been a few reports of ski cuts causing small loose avalanches. We expect avalanche activity to increase rapidly as the storm arrives.
Confidence
Timing of incoming weather systems is uncertain
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.